Variations of the type of method described are known. However, these methods generally seek only for as high a conversion as possible (DE-OS 28 05 702) and do not consider a distillative purification in the case of the higher-boiling acrylates and methacrylates, e.g. trimethylol propane trimethacrylate Published German Patent Application DE-OS 27 44 641.
Apha color indices according to Hazen of 15 (DIN 55409) can be achieved in the preparation of higher-molecular alkyl acrylates and alkyl methacrylates if the transesterification is carried out according to Published German Patent Application DE-OS 23 17 226 in the presence of a small amount of absorbent carbon as polymerization inhibitor. However, if the description of this patent is followed, the desired degrees of purity can not be achieved by means of a vacuum distillation of the type suggested in British Patent 962,928.